This Interagency Agreement serves as a follow on to the May 6, 2005 Memorandum of Agreement between NIEHS, National Cancer Institute (NCI), and CDC for sample preparation and analysis activities associated with the NIEHS/NCI Breast Cancer and the Environment Research Centers Program (BCERC). The three BCERC sites involved in the Epidemiology Project (Fox Chase Cancer Center, University of California at San Francisco, and University of Cincinnati), under the direction of the Center Directors, are responsible for collecting, storing, and shipping samples;analyzing data-based bioassays of the samples;collecting all relevant medical and biologic information from the study participants;safeguarding the data and the privacy of study participants;and ensuring all associated quality control for an epidemiologic study of the role of genes and environmental exposures on puberty in young girls. The parties to this follow on agreement are the Division of Laboratory Sciences (DLS) of CDC[unreadable]s National Center for Environmental Health, which develops and applies advanced laboratory technology in the area of exposure to toxic substances and the NIEHS. The collaboration between NIEHS and CDC for environmental exposure assessments as a part of the BCERC epidemiology project will facilitate common goals in understanding the biologic basis for the effects of environmental factors on the age of onset of and progression through puberty of a diverse population of pre- and peri-pubertal girls in the United States.